<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
hello world
<script>
    var timestamp1 = Date.parse(new Date());
    var timestamp2 = (new Date()).valueOf();
    var timestamp3 = new Date().getTime();
    console.log(timestamp1);
    console.log(timestamp2);
    console.log(timestamp3);
    /**
     * 第一种：获取的时间戳是把毫秒改成000显示,
     * 第二种和第三种是获取了当前毫秒的时间戳.
     */
</script>
</body>
</html>